A man murdered his girlfriend following a massive fight, posted grisly photos of her naked body online and scrawled 'she killed me first' over a picture in her room before fleeing, police have said.

David Kalac, 33, surrendered to cops in Wilsonville, Oregon late on Wednesday night after a lengthy manhunt, during which he managed to elude authorities in a high-speed chase.

His arrest came hours after the body of his girlfriend, 30-year-old Amber Lynn Coplin, was found inside her Port Orchard, Washington home by her 13-year-old son and estranged husband.

The boy told detective that he had heard Kalac and Coplin arguing loudly on Monday night, and witnesses said they heard what sounded like a violent argument and loud thumping inside the home.

Arrest: David Kalac, 33, left in his booking photo and right after he was arrested, surrendered to police in Oregon on Wednesday after cops had a warrant out for his arrest for killing a woman in Washington

The next morning, the teenager awoke to find Kalac gone and thought his mother was still sleeping as he headed to school, court documents show.

He returned home from school on Tuesday morning and took a nap, but when he awoke later that afternoon, his mother's gold 2001 Ford Focus was gone.

The youngster went to check on his mother and 'found her unresponsive' so he called his father - Coplin's estranged husband - who came over and found the body just before 3.30pm on Tuesday.

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He called 911 and reported that Coplin's face was 'bashed in', that her car was missing and that she was bloody and bruised, according to court documents.

Police arrived on the scene within minutes and found Amber Lynn murdered among horrifying messages scrawled throughout the room.

By her head, they found her driver's license with the word 'dead' written across it. The words 'bad news' were written on blinds, while 'she killed me first' was written on a picture on the wall.

Tragedy: Amber Lynn Coplin's body was found by her 13-year-old son, right, in her bedroom on Tuesday

Just half an hour before her estranged husband called police, mysterious messages appeared on the photo sharing website 4chan apparently showing her murdered naked body.

'Check the news for Port Orchard Washington in a few hours,' said the message, viewed by MailOnline. 'Her son will be home from school soon. He'll find her, then call the cops.

'I just wanted to share the pics before they find me. I bought a BB gun that looks realistic enough. When they come, I'll pull it and it will be suicide by cop.

'I understand the doubts. Just check the f***ing news. I have to lose my phone now.'

In another graphic message, the poster added that 'it's way harder to strangle someone than it looks in the movies' and described how she had fought hard for her life.

Police said that Kalac also texted a friend from his cellphone on Tuesday morning telling the friend that he would read about him in the news.

Heartbreaking: Coplin's teenage son called his dad (right) - Coplin's estranged husband - after he found his mother's unresponsive body on Tuesday afternoon. Paul Coplin then called authorities

Deputies have confirmed that the gruesome photos are of the victim and the crime scene.

'He's our primary suspect,' sheriff's Deputy Scott Wilson said on Wednesday. 'It stands to reason that in all likelihood he is the person who posted those photographs.'

On Wednesday, police put out a warrant for Kalac's arrest and urged the public to contact them if they saw Coplin's missing car.

Kalac drove three hours to Portland, where a police officer spotted the vehicle about 1.15am on Wednesday.

After a high-speed chase, Kalac swerved into on-coming traffic, forcing police to call off their pursuit.

But on Wednesday night, Kalac was arrested at a transit center in Wilsonville, about 20 miles south of Portland.

An officer was patrolling the area when the man came out of a wooded area near a parking lot, Clackamas County sheriff's Sergeant Nate Thompson said.

Scene: She was found murdered inside her Port Orchard, Washington home, pictured, on Tuesday afternoon - just half an hour after the killer apparently posted grisly images of her naked body online

Sick: Kalac, her boyfriend, also allegedly left messages scrawled inside her bedroom, including 'she killed me first' on a picture and 'dead' across the driving license, which was found near her head

'He basically said, "I have a warrant for my arrest",' Thompson said.

Kalac was cooperative but provided no details about how he got to Wilsonville, the spokesman said.

Washington state detectives have arrived in Portland and hoped to interview him, as well as take possession of the dead woman's car, which was found in Portland.

Kalac has been charged with second-degree murder in the slaying. He was transported to Portland, where he was being held on $2 million bail.

Kalac also has a criminal history in Washington state and Virginia that includes convictions for assault, burglary and DUI, Kitsap County, Washington, records have revealed.

THE FORUM WHERE USERS POST ANONYMOUSLY: WHAT IS 4CHAN?

Before David Kalac was arrested, he allegedly posted photographs of Amber Lynn Coplin's dead body on 4chan.

Created in 2003 by a 15-year-old high school student from New York City, Christopher Poole, 4chan was originally meant to be a forum to discuss Japanese anime and post photos. The image board site soon grew to by much more, and quickly became one of the biggest websites in the world.

The biggest difference between 4chan and other websites however is that it allows commenters and contributors to post anonymously, giving many free reign to do things they would not do otherwise.

While this has led to the site producing some amusing and funny pranks, many are horrific and have led to the arrest of the person or persons who created them.

LOLCats – The Internet obsession with cats actually began back in 2005 when one 4Chan commenter decided to post as a photo of a cat waiting for Caturday. It all took off from there.

Rickroll – In 2007, a fake link to the trailer for the video game Grand Theft Auto IV was posted to the site after the website of the game’s publisher, Rockstar Games, crashed. Instead of seeing a look at the highly anticipated new game, eager fans were instead taken to the YouTube page for the Rick Astley music video 'Never Gonna Give You Up'.

Steve Jobs Death – In 2008 members on the site spread a false rumor that Steve Jobs was dead, causing Apple stock prices to plummet a whopping 10% in one day.

Send Justin Bieber To North Korea – Justin Bieber has long been a target for the site, and in 2010 he wanted fans to tell him where they wanted him to go on his My World Tour. 4Chan users hacked his site, and the overwhelming winner was North Korea. The Canadian did not ultimately make the trip.

Jessi Slaughter – In what may have been their most vicious attack to date, members of 4Chan began to cyberbully an 11-year-old girl after claiming she was having a relationship with an older man. They posted her address, called her house, and spread false rumors and reports about her and her family. The threats got so bad that the young girl was put in police protection at one point.

Trayvon Martin – In 2012 a 4Chan hacker and white supremacist falsely claimed they had hacked into Trayvon Martin’s email and Facebook accounts after his murder, posting emails and photos that were supposed to back up the false claim that Martin was a drug addict and dealer.

Cutting For Bieber – In early 2013, a member of 4Chan created an elaborate Twitter hoax in which they urged fans of Justin Bieber to cut themselves so the pop star would stop smoking weed. Soon, the hashtags #cutforbieber and #cuttingforbieber amassed numerous photos of fans who claimed to have slashed their wrists and forearms over Bieber's drug use.

Taylor Swift's Biggest Fan – In 2013 Taylor Swift, like Bieber, wanted fans to help her out with her next contest. She was looking for her biggest fan, and 4Chan made sure the winner was a 39-year-old man named Charles who wanted to ‘sniff Taylor’s hair.’ The contest was ultimately cancelled.

Celebrity Nude Leaks – Nothing 4Chan has done has had a bigger impact however than the leaking of hundreds of nude photos of celebrities in 2014, something that eventually led to the FBI getting involved. Victims included A-list stars like Jennifer Lawrence, Gabrielle Union, Kim Kardashian and Rihanna.